How to chase unpaid invoices: a UK small business guide
Late payment is one of the most common jobs in a small business office, and one of the easiest to put off. This guide covers when an invoice to another business counts as late under UK law, a simple reminder schedule, and what you can add to the bill if it stays unpaid. It covers invoices to other businesses and public bodies, not to consumers.
When an invoice is legally late
GOV.UK says that if you agree a payment date, it must usually be within 30 days for public authorities or 60 days for business transactions. You can agree a longer period than 60 days between businesses, but it must be fair to both.
If you don't agree a payment date, the law says payment is late 30 days after the customer gets the invoice, or 30 days after you deliver the goods or provide the service, if that's later.
So the first step happens before you send any reminder: put your payment terms and the due date on every invoice.
A simple reminder schedule
Use a steady, polite schedule so every late invoice gets the same reminders:
- A few days before the due date: a friendly note with the invoice attached, the amount and the due date.
- On the due date: a short reminder that payment is due today, with your bank details.
- 7 days late: a stronger reminder. Ask whether there's a problem with the invoice and when you can expect payment.
- 14 to 30 days late: a final reminder that says you'll add statutory interest and recovery costs if it isn't paid by a set date.
- After that: a formal letter, then consider formal steps to recover the debt.
Keep every reminder short. Include the invoice number, the amount, the due date and how to pay, so the customer can pay without having to ask.
Statutory interest and fixed recovery costs
If another business pays late, GOV.UK says you can claim:
- Statutory interest: 8% plus the Bank of England base rate for business-to-business transactions. You can't claim statutory interest if your contract sets a different interest rate.
- A fixed sum for the cost of recovering the debt, once for each payment, on top of the interest:
| Amount of debt | What you can charge |
|---|---|
| Up to £999.99 | £40 |
| £1,000 to £9,999.99 | £70 |
| £10,000 or more | £100 |
GOV.UK says to send a new invoice if you decide to add interest to the money you're owed. Check the current Bank of England base rate when you work it out.
Wording for a first reminder
Hi [name], just a reminder that invoice [number] for [amount] is due on [date]. I've attached a copy. You can pay by bank transfer to [details]. Thanks, [your name]
Where an assistant fits
Tracking due dates and preparing reminders is routine work, so an assistant can do it. The reminders go out in your name, though, so a good set-up has the assistant prepare each one and you approve it first.
That's how we set up our done-for-you service, Grok Bot setup by Your Evenings. Invoice reminders are one of the jobs it can take on: it prepares them for your OK. We set it up to ask for your approval before it sends or pays. Your Evenings is an independent service and is not affiliated with or endorsed by Grok Bot or its maker, SpaceX Super Intelligence LLC (SpaceXSI).
Questions
When does an invoice become late in the UK?
If you agreed a payment date, payment is due by that date. If you didn't, GOV.UK says it's late 30 days after the customer gets the invoice, or after you deliver the goods or service if that's later.
How much interest can I charge on a late invoice?
For business-to-business transactions, statutory interest is 8% plus the Bank of England base rate, unless your contract sets a different rate. You can also charge a fixed recovery sum of £40, £70 or £100, depending on the amount of the debt.
How many reminders should I send before taking further steps?
There's no fixed number. A common schedule is a reminder before the due date, one on the day, one at 7 days late and a final reminder at 14 to 30 days late that mentions interest and recovery costs.
Sources
- GOV.UK: Late commercial payments: when a payment becomes late (read 31 October 2026)
- GOV.UK: Interest on late commercial payments (read 31 October 2026)
- GOV.UK: Claim debt recovery costs on late payments (read 31 October 2026)
- Your Evenings Ltd, Grok Bot setup service page (read 31 October 2026), for what our service does.
This guide summarises the official sources above. It isn't legal advice.
Written with AI assistance by the Your Evenings team at Your Evenings Ltd. Last updated 31 October 2026.